Positional mapping and identification of novel quantitative trait locus responsible for UV-B radiation tolerance in soybean [<Emphasis Type="Italic">Glycine max</Emphasis> (L.) Merr.]

The amount of ultraviolet-B radiation (UV-B: 280–320 nm) reaching Earth’s surface is expected to increase due to stratospheric ozone depletion. This could cause significant biological damage in plants, and serious yield losses in crops. Soybean [Glycine max (L.) Merr.], a major legume crop, is known to be sensitive to UV-B radiation. Thus, developing a UV-B-tolerant soybean is an efficient and economical strategy to avoid putative yield losses through increased UV-B irradiation. The objective of this study is to identify the novel quantitative trait loci (QTLs) for UV-B tolerance in the soybean using high-density genetic linkage mapping. One hundred and fifteen F8-derived F12 recombinant inbred lines developed from a cross between the UV-B susceptible cultivar, Keunol, and a tolerant breeding line, Iksan 10, were used. Three categories of phenotypic traits were scored: degree of leaf color change, degree of leaf shape change and degree of total plant damage. A genome-wide molecular genetic linkage map containing 8691 single nucleotide polymorphism markers was constructed using the recently developed genotyping platform, the 180K Axiom SoyaSNP assay. Using composite interval mapping analysis, one major candidate QTL on chromosome 7 was identified and designated qUVBT1, and is located between two flanking makers, AX-90437826 and AX-90317546, within 1.6 cM, corresponding to a ~24-kb physical region with six annotated gene models. One of them is a homolog of yeast RAD23, which has previously been reported to be a UV excision repair protein. This result could be valuable in breeding new UV-B-tolerant soybean cultivars and elucidating the UV-B response mechanism in soybean plants.     

Paeonia lactiflora Enhances the Adhesion of Trophoblast to the Endometrium via Induction of Leukemia Inhibitory Factor Expression

In the present study, we investigated the role of Paeonia lactiflora Pall. extract on embryo implantation in vitro and in vivo. A polysaccharides depleted-water extract of P. lactiflora (PL-PP) increased LIF expression in human endometrial Ishikawa cells at non-cytotoxic doses. PL-PP significantly increased the adhesion of the human trophectoderm-derived JAr spheroids to endometrial Ishikawa cells. PL-PP-induced LIF expression was decreased in the presence of a p38 kinase inhibitor SB203580 and an MEK/ERK inhibitor U0126. Furthermore, endometrial LIF knockdown by shRNA reduced the expression of integrins β3 and β5 and adhesion of JAr spheroids to Ishikawa cells. In vivo administration of PL-PP restored the implantation of mouse blastocysts in a mifepristone-induced implantation failure mice model. Our results demonstrate that PL-PP increases LIF expression via the p38 and MEK/ERK pathways and favors trophoblast adhesion to endometrial cells.     

Mixotrophy in the newly described phototrophic dinoflagellate Woloszynskia cincta from western Korean waters: feeding mechanism, prey species and effect of prey concentration

Woloszynskia species are dinoflagellates in the order Suessiales inhabiting marine or freshwater environments; their ecophysiology has not been well investigated, in particular, their trophic modes have yet to be elucidated. Previous studies have reported that all Woloszynskia species are photosynthetic, although their mixotrophic abilities have not been explored. We isolated a dinoflagellate from coastal waters in western Korea and established clonal cultures of this dinoflagellate. On the basis of morphology and analyses of the small/large subunit rRNA gene (GenBank accession number=FR690459), we identified this dinoflagellate as Woloszynskia cincta. We further established that this dinoflagellate is a mixotrophic species. We found that W. cincta fed on algal prey using a peduncle. Among the diverse prey provided, W. cincta ingested those algal species that had equivalent spherical diameters (ESDs) ≤12.6 μm, exceptions being the diatom Skeletonema costatum and the dinoflagellate Prorocentrum minimum. However, W. cincta did not feed on larger algal species that had ESDs≥15 μm. The specific growth rates for W. cincta increased continuously with increasing mean prey concentration before saturating at a concentration of ca. 134 ng C/ml (1,340 cells/ml) when Heterosigma akashiwo was used as food. The maximum specific growth rate (i.e. mixotrophic growth) of W. cincta feeding on H. akashiwo was 0.499 d(-1) at 20 °C under illumination of 20 μE/m(2) /s on a 14:10 h light-dark cycle, whereas its growth rate (i.e. phototrophic growth) under the same light conditions without added prey was 0.040 d(-1). The maximum ingestion and clearance rates of W. cincta feeding on H. akashiwo were 0.49 ng C/grazer/d (4.9 cells/grazer/d) and 1.9 μl/grazer/h, respectively. The calculated grazing coefficients for W. cincta on co-occurring H. akashiwo were up to 1.1 d(-1). The results of the present study suggest that grazing by W. cincta can have a potentially considerable impact on prey algal populations.     

Insulin-mimetic and insulin-sensitizing activities of a pentacyclic triterpenoid insulin receptor activator

Five pentacyclic triterpenoids isolated from Campsis grandiflora were tested for insulin-mimetic and insulin-sensitizing activity. The compounds enhanced the activity of insulin on tyrosine phosphorylation of the IR (insulin receptor) beta-subunit in CHO/IR (Chinese-hamster ovary cells expressing human IR). Among the compounds tested, CG7 (ursolic acid) showed the greatest enhancement and CG11 (myrianthic acid) the least. We characterized the effect of CG7 further, and showed that it acted as an effective insulin-mimetic agent at doses above 50 mug/ml and as an insulin-sensitizer at doses as low as 1 mug/ml. Additional experiments showed that CG7 increased the number of IRs that were activated by insulin. This indicates that a major mechanism by which CG7 enhances total IR auto-phosphorylation is by promoting the tyrosine phosphorylation of additional IRs. CG7 not only potentiated insulin-mediated signalling (tyrosine phosphorylation of the IR beta-subunit, phosphorylation of Akt and glycogen synthase kinase-3beta), but also enhanced the effect of insulin on translocation of glucose transporter 4 in a classical insulin-sensitive cell line, 3T3-L1 adipocytes. The results of the present study demonstrate that a specific pentacyclic triterpenoid, CG7, exerts an insulin-sensitizing effect as an IR activator in CHO/IR cells and adipocytes. The enhancement of insulin activity by CG7 may be useful for developing a new class of specific IR activators for treatment of Type 1 and Type 2 diabetes.     

A synthetic de-greening gene circuit provides a reporting system that is remotely detectable and has a re-set capacity

Plants have evolved elegant mechanisms to continuously sense and respond to their environment, suggesting that these properties can be adapted to make inexpensive and widely used biological monitors, or sentinels, for human threats. For a plant to be a sentinel, a reporting system is needed for large areas and widespread monitoring. The reporter or readout mechanism must be easily detectable, allow remote monitoring and provide a re-set capacity; all current gene reporting technologies fall short of these requirements. Chlorophyll is one of the best-recognized plant pigments with an already well-developed remote imaging technology. However, chlorophyll is very abundant, with levels regulated by both genetic and environmental factors. We designed a synthetic de-greening circuit that produced rapid chlorophyll loss on perception of a specific input. With induction of the de-greening circuit, changes were remotely detected within 2 h. Analyses of multiple de-greening circuits suggested that the de-greening circuit functioned, in part, via light-dependent damage to photosystem cores and the production of reactive oxygen species. Within 24–48 h of induction, an easily recognized white phenotype resulted. Microarray analysis showed that the synthetic de-greening initiated a process largely distinct from normal chlorophyll loss in senescence. Remarkably, synthetically de-greened white plants re-greened after removal of the inducer, providing the first easily re-settable reporter system for plants and the capacity to make re-settable biosensors. Our results showed that the de-greening circuit allowed chlorophyll to be employed as a simple but powerful reporter system useful for widespread areas.     

Time-course alterations of Toll-like receptor 4 and NF-κB p65, and their co-expression in the gerbil hippocampal CA1 region after transient cerebral ischemia

Innate immune system is very important to modulate the host defense against a large variety of pathogens. Toll-like receptors (TLRs) play a key role in controlling innate immune response. Among TLRs, TLR4 is a specific receptor for lipopolysaccharide and associated with the release of pro-inflammatory cytokines. In the present study, we investigated ischemia-related changes of TLR4 immunoreactivity and its protein level, and nuclear factor κB (NF-κB) p65 immunoreactivity regarding inflammatory responses in the hippocampal CA1 region after 5 min of transient cerebral ischemia to identify the correlation between transient ischemia and inflammation. In the sham-operated group, TLR4 immunoreactivity was easily detected in pyramidal neurons of the hippocampal CA1 region (CA1). TLR4 immunoreactivity in pyramidal neurons was distinctively decreased after ischemia/reperfusion (I/R); instead, based on double immunofluorescence study, TLR4 immunoreactivity was expressed in non-pyramidal neurons and astrocytes from 2 days postischemia. In addition, TLR4 protein level was lowest at 1 day postischemia and highest 4 days after I/R. On the other hand, NF-κB p65 immunoreactivity was not detected in the CA1 of the sham-operated group, and NF-κB p65 immunoreactivity was not observed until 1 day after I/R. However, NF-κB p65 immunoreactivity began to be expressed in astrocytes at 2 days postischemia, and the immunoreactivity was strong 4 days postischemia. Our results indicate that TLR4 and NF-κB p65 immunoreactivity are changed in CA1 pyramidal neurons and newly expressed in astrocytes, not in microglia, in the CA1 region after transient cerebral ischemia.     

The role ofH-2 regions in overcoming tissue incompatibility

Neonatal transplantation tolerance to the products of theH-2 ^b complex was induced in B10.A (H-2 ^a ) mice. On the basis of the survival of skin allografts it was found that antigens determined by theD region of theH-2 ^b complex (of the B10.A(2R) strain) were most easily overcome and that tolerance to the products of theD end of theH-2 complex (of the B10.A(4R) strain) was also easy to induce. The antigens produced by theK end ofH-2 (of the B10.A(5R) and B10.A(3R) strains) represented a stronger incompatibility barrier and a difference in the entireH-2 ^b complex caused strongest resistance to tolerance induction. When tolerance to the products of the entireH-2 ^b complex was induced in newborn B10.A mice, and the neonatally treated animals were grafted simultaneously with five different grafts, those disparate at theK end ofH-2 and in the entireH-2 region were rejected in some animals, while the grafts disparate at theD end of H-2 remained intact in the same mice. No dependence on theI-J subregion was observed in this system. Furthermore, tolerance was more easily inducible in male than in female B10.A mice.     

Comparison of Expression of Inflammatory Cytokines in the Spinal Cord Between Young Adult and Aged Beagle Dogs

Aging is an inevitable process that occurs in the whole body system accompanying with many functional and morphological changes. Inflammation is known as one of age-related factors, and inflammatory changes could enhance mortality risk. In this study, we compared immunoreactivities of inflammatory cytokines, such as interleukin (IL)-2 (a pro-inflammatory cytokine), its receptor (IL-2R), IL-4 (an anti-inflammatory cytokine), and its receptor (IL-4R) in the cervical and lumbar spinal cord of young adult (2–3 years old) and aged (10–12 years old) beagle dogs using immunohistochemistry and western blotting. IL-2 and IL-2R-immunoreactive nerve cells were found throughout the gray matter of the cervical and lumbar spinal cord of young adult and aged dogs. In the spinal cord neurons of the aged dog, immunoreactivity and protein levels were apparently increased compared with those in the young adult dog. Change patterns of IL-4- and IL-4R-immunoreactive cells and their protein levels were also similar to those in IL-2 and IL-2R; however, IL-4 and IL-4R immunoreactivity in the periphery of the neuronal cytoplasm in the aged dog was much stronger than that in the young adult dog. These results indicate that the increase of inflammatory cytokines and their receptors in the aged spinal cord might be related to maintaining a balance of inflammatory reaction in the spinal cord during normal aging.     

A Randomised Trial Evaluating the Safety and Immunogenicity of the Novel Single Oral Dose Typhoid Vaccine M01ZH09 in Healthy Vietnamese Children

Background

The emergence of drug resistant typhoid fever is a major public health problem, especially in Asia. An oral single dose typhoid vaccine would have major advantages. M01ZH09 is a live oral single dose candidate typhoid vaccine containing Salmonella enterica serovar Typhi (Ty2 aroC ⁻ ssaV ⁻) ZH9 with two independently attenuating deletions. Studies in healthy adults demonstrated immunogenicity and an acceptable safety profile.

Objectives

We conducted a randomised placebo controlled, single-blind trial to evaluate the safety and immunogenicity of M01ZH09 in healthy Vietnamese children aged 5 to 14 years.

Methods

Subjects were randomly assigned to receive either a nominal dose of 5×10⁹ CFU of M01ZH09 or placebo and were followed up for 28 days. The primary safety outcome was the proportion of subjects with any adverse event attributed to M01ZH09. The primary immunogenicity endpoint was the proportion of subjects who showed a positive immune response to M01ZH09 in the Salmonella Typhi lipopolysaccharide (LPS) specific serum IgA and IgG ELISA.

Principal Findings

One hundred and fifty-one children were enrolled, 101 subjects received M01ZH09 and 50 subjects received placebo. An intention to treat analysis was conducted. There were no serious adverse events and no bacteraemias. In the M01ZH09 group, 26 (26%; 95% CI, 18–5%) of 101 subjects experienced adverse events compared to 11 (22%; 95% CI, 12–36%) of 50 subjects in the placebo group (odds ratio (OR) [95%CI]  = 1.23 [0.550–2.747]; p = 0.691). Faecal shedding of S. Typhi (Ty2 aroC ⁻ ssaV ⁻) ZH9 was detected in 51 (51%; 95% CI, 41–61%) of 100 M01ZH09 subjects. No shedding was detected beyond day 3. A positive immune response, defined as 70% increase (1.7 fold change) in LPS specific serum IgG (day 14 or 28) and/or 50% increase (1.5 fold change) in LPS specific serum IgA (day 7 or 14) from baseline was detected in 98 (97%; 95% CI, 92–99%) of 101 M01ZH09 recipients and 8 (16%; 95% CI, 7–29%) of 50 placebo recipients. Twenty-eight (100%; 95% CI, 88–100%) of 28 vaccine recipients who were evaluated in the LPS specific IgA ELISPOT assay showed a positive response compared to none of the 14 placebo recipients tested.

Conclusions

This was the first phase II trial of a novel oral candidate typhoid vaccine in children in an endemic country. M01ZH09 had an appropriate safety profile and was immunogenic in children.

Trial Registration

Controlled-trials.comISRCTN91111837